Figure 3. Phylogenetic trees of the eight gene segments of the influenza viruses.

The tree was created by the neighbor-joining method and bootstrapped with 1,000 replicates. The bootstrap numbers are given for each node. Only bootstrap values above 80 are shown. Viruses isolated in the present study are in bold. Abbreviations used in virus designations are as follows: Ck, chicken; Dk, duck; Sw, swine; Tk, turkey.